Integrating Adventurer Conqueror King System II (ACKS II) with the legendary, chaotic, and maximum-gonzo DNA of Dave Hargrave’s Arduin Grimoires - Converting Welcome to Skull Tower over to ACKS II

 Converting David A. Hargrave’s legendary 1978 supplement, The Arduin Grimoire Vol. II: Welcome to Skull Tower, into ACKS II (Adventurer Conqueror King System II) provides your campaign with a central hub for planar travel and dungeon-crawling. This blog post picks right up from Integrating Adventurer Conqueror King System II (ACKS II) with the legendary, chaotic, and maximum-gonzo DNA of Dave Hargrave's Arduin Grimoires - Random Fey & Fairy Encounters

In the original texts, Skull Tower isn't just a single mega-dungeon layout—it is the quintessential planar multi-level megastructure, a nexus point of the multiverse where high-tech space marines and ancient liches rub shoulders.

Converting it involves structuring its multi-dimensional economy, handling its lethal traps using ACKS II proficiencies, and managing it as a high-level domain.

1. Establishing Skull Tower as a Class I Market Nexus

In ACKS II, a Class I Market City represents a massive metropolis with access to almost every conceivable luxury, resource, and mercenary pool. Skull Tower functions as a vertical, highly militarized Class I Market City nestled in the wilderness.

• Planar Infrastructure: Because its gates pull from infinite realities, ignore standard regional population density math when stocking its markets. Assume a virtual population of 100,000+ equivalent consumers moving through its gates.

• The Market Modifier: Apply a permanent +2 bonus to all Market Availability rolls for Technic Salvage, Alien Slaves, Magic Items, and Rare Monster Parts. Conversely, standard agricultural goods (grain, livestock) face a 300% markup due to the barren nature of the surrounding terrain.

2. Converting the Dungeon Ecology & Levels

Skull Tower is notoriously high-lethality. When converting the legendary encounter tables and floor layouts into the strict mathematical framework of ACKS II, map them into precise Dungeon Tiers:

Tier Translation Matrix

Skull Tower Level	ACKS II Dungeon Level Equivalent	Typical Factions / Denizens	Wandering Monster Metric
Upper Spires (1–3)	Level 4–6 (Challenging)	Phraint Hives, Disgraced Mages, Rogue Technos	Roll 1d6 every 2 turns; 1 indicates an encounter.
The Nexus Plazas (4–6)	Level 7–9 (Dangerous)	Interstellar Pirates, Deodand Slavers, Demons	Roll 1d6 every turn; 1 indicates an encounter. Heavy traffic.
The Depths & Vaults (7+)	Level 10+ (Legendary)	Chronomancers, Cosmic Horrors, Dead Gods	Checks include exposure to Poison/Radiation hazards.

The "Room of Respite" Conversion

Skull Tower famously features single, isolated safe-rooms on every floor where the laws of the dungeon are suspended.

• ACKS II Integration: Treat these as localized Sanctuary Zones. Characters resting inside a Room of Respite heal at double the normal rate and are completely immune to random encounter checks. However, characters cannot remain in a single Room of Respite for more than 24 hours without triggering a structural reality-shift that teleports them randomly into the wilderness.

3. Trap and Hazard System Translation

Hargrave’s original modules are packed with instantaneous "save-or-die" style traps, radiation pools, and acid pits. ACKS II formalizes these into structured saving throws and proficiency checks.

• The Technology Trap: If a trap features advanced wiring, lasers, or mechanical sensors, a standard Thief's Find/Remove Traps skill suffers a -4 penalty unless they possess the Ancient Lore (Technology) proficiency or are of the Techno class.

• Radiation Pools: Replace Arduinian "Radiation Points" directly with the ACKS II Poison/Radiation Saving Throw.

  • Mild Exposure: Failure inflicts 1d6 temporary Constitution damage.

  • Severe/Nuclear Exposure: Failure causes instant systemic necrosis (treat as a Death result on the mortal wounds table if not treated within 1 turn via a Sub-Dermal Coagulation Matrix or high-level magic).

4. Late-Game Domain Play: Capturing or Governing the Tower

If your party reaches levels 9–14 (Conqueror to King phase) and successfully cleanses or claims a portion of Skull Tower, the domain-level mechanics of ACKS II shift into hyper-gear.

Domain Revenue: The World-Gate Tariff

Instead of calculating land income based on peasant farming families (which requires vast agricultural acreage), a domain centered on Skull Tower generates wealth via Planar Tariffs:

[Planar Merchants / Explorers] ---> [The Skull Gates] ---> [10% Flat Transit Tax]
                                                                  |
                                                       Yields: 5,000 - 30,000 gp/month

• The ruler can levy a flat 10% transit tax on all planar merchants, mercenaries, and adventuring parties passing through the tower's gates.

• The Garrison Upkeep Check: Because Skull Tower is a focal point for cross-dimensional factions, the domain requires a massive garrison. The monthly upkeep for defenders—including specialized anti-magic units, golems, and heavy-weapons cohorts—must equal at least 50% of the gross gate tariff revenue to prevent an immediate coup or planar invasion.

Garrisoning with Exotic Units

Skull Tower allows you to recruit forces completely unavailable in standard fantasy realms. When assembling an army using the Domains at War framework, the ruler can hire:

• Phraint Phalanxes: Treated as heavy infantry with elite morale (+2) and natural armor piercing traits.

• Techno Sapper Squads: Disarm castle fortifications and traps at triple the speed of traditional engineers using high-frequency plasma torches.

To run the World Gates of Skull Tower as a dynamic economic driver using the ACKS II domain and market mechanics, the gate is treated as a Class I Planar Market Venture. Instead of tracking individual merchant wagons, a ruler or Judge tracks the Monthly Shipping Manifests.

This system uses the ACKS II trade engine but introduces Planar Flux, allowing domain rulers to tax exotic imports or export terrestrial goods to alien dimensions.

1. The Gate Economy Framework

Every month during the Domain Turn, the ruler calculates the Gate Trade Value (GTV). The baseline GTV is determined by the size and stability of the market surrounding the tower:

• Skull Tower Ruins (Unsecured / Wild): Base GTV = 2,500 gp

• Fortified Borderland Outpost: Base GTV = 10,000 gp

• Secured Planar Free-Port (Class II Market Equivalent): Base GTV = 40,000 gp

The Tariff and Unrest Mechanics

The ruler can levy a Planar Tariff on imports and exports moving through the gates:

• Standard Tariff (5%): Normal operations. Generates standard revenue.

• Aggressive Tariff (15%): Double revenue, but increases local Domain Unrest by +1 due to black-market smuggling rings springing up in the catacombs.

• Prohibitive Tariff (30%): Triple revenue, but increases Domain Unrest by +3 and triggers a roll on the Planar Smuggler Strike event table.

2. Monthly Planar Flux Table (d100)

At the start of each month, roll 1d100 to determine which dimensional faction or empire currently holds the dominant trade manifest through the Skull Tower World Gates. This modifies the base GTV and dictates available goods.

d100	Planar Trade Manifest	GTV Modifier	Primary Import (Available to Buy)	Primary Export (Demanded by Gate)
01–15	The Techno-Foundries of Omega-Prime	+50%	Power Cells, Cyber-Parts, Lasers	Raw Iron Ore, Unrefined Mithril
16–30	The Obsidian Slavelords of the Red Sun	+20%	Exotic Beasts, Gladiators, Narcotics	Terrestrial Grain, Fresh Water
31–45	The Phraint Chitin-Hive Conglomerate	+0%	Hyper-Dense Alloys, Composite Bows	Alchemical Acid, Honey / Sugar
46–60	The Astral Merchant Cartel of the Void	+100%	Ancient Relics, Rare Spells, Gems	Finished Luxury Goods, Artwork
61–75	The Chrono-Dilation Free-Traders	-25%	Liquid Time, Preserved Artifacts	Historical Texts, Living Livestock
76–90	The Abyssal Flesh-Weavers	+10%	Bio-Constructs, Mutagenic Chem-Stims	Humanoid Corpses, Souls / Essence
91–00	The Cosmic Storm (Gate Malfunction)	-100%	None (Gate is physically unstable)	None (Trade route collapsed)

3. Exotic Import/Export Goods Table

When a player characters or independent merchants want to actively buy or sell bulk merchandise through the gate, roll 1d20 on this table to see what specialized cargo containers have arrived on this month's manifests.

d20	Cargo Manifest Item	Lot Size	Base Purchase Cost	Terrestrial Market Value	Risk / Legality Factor
1	Omega-Prime Power Cells	1 Crate (50 cells)	10,000 gp	15,000 gp	Highly volatile; explodes if exposed to magical fire.
2	Refined Plasteel Sheeting	10 Tons	5,000 gp	7,500 gp	Can be used to reduce Stronghold building costs by 20%.
3	Deodand Hunting Hounds	Pack of 1d6	3,000 gp	4,500 gp	Require raw meat daily; 5% chance per month to turn on handlers.
4	Phraint Chitin Armor Lots	10 Suits	4,000 gp	6,000 gp	Extremely light plate-equivalent armor; highly sought by mercenaries.
5	Hyper-Space Narcotics (Lotus-Dust)	1 Small Case	2,000 gp	8,000 gp	Illegal. Triggers a city-wide guard inspection if moved out of hex.
6	Stasis-Preserved Alien Seeds	1 Vault Box	6,000 gp	9,000 gp	Can be planted to permanently increase a domain's land yield by 5%.
7	Cybernetic Limb Replacements	1d4 Units	8,000 gp	12,000 gp	Requires a Techno or Master Cyberneticist to safely implant.
8	Liquid Promethium Jet-Fuel	50 Barrels	5,000 gp	7,000 gp	Highly explosive; counts as heavy ammunition for siege engines.
9	Crashed Probe Salvage Scrap	1 Bulk Lot	3,000 gp	Varies	Yields 1d4+1 rolls on the Techno Workshop Crafting Table.
10	Mutagenic Growth Serums	10 Vials	4,000 gp	6,000 gp	Used to speed up monster cross-breeding projects by 50% in ACKS II.
11	Astral Silk Textiles	20 Bolts	3,500 gp	5,500 gp	High-end luxury trade good; doubles standard merchant caravan profit.
12	Vibro-Blade Weapon Shipments	20 Swords	6,000 gp	9,000 gp	Weapons ignore leather/padded armor entirely; elite troop gear.
13	Unstable Fusion Reactor Cores	1 Core	15,000 gp	25,000 gp	Required to power Arduinian Heavy Power Armor or Foundry bases.
14	Alien Slave Cohorts	50 Laborers	2,500 gp	4,000 gp	Reduces domain garrison or construction labor costs by 10%.
15	Holographic Grid Projectors	2 Units	7,000 gp	10,000 gp	Can be installed in strongholds to grant defense against sieges.
16	Interstellar Spice Cargo	5 Crates	4,000 gp	8,000 gp	Highly sought after by terrestrial emperors and high nobility.
17	Malfunctioning Labor Droids	1d4 Droids	5,000 gp	7,500 gp	Can replace 20 human laborers each if repaired by a Techno.
18	Void-Hardened Steel Ingots	5 Tons	8,000 gp	12,000 gp	Used to forge weapons with a permanent +1 non-magical hit bonus.
19	Memory Disks (Ancient Data)	1 Cache	10,000 gp	Varies	Grants an automatic success on one future technological blueprint roll.
20	Bio-Luminescent Light Spores	100 Jars	1,000 gp	2,000 gp	Permanent cold-light source; heavily demanded by subterranean miners.

4. Resolving a Trade Turn

To run a transaction through the Skull Tower World Gates during the monthly phase:

1. Check Planar Flux: Roll 1d100 to find out who is trading through the gate this month and apply the GTV modifier.

2. Calculate Tariff Income: The domain ruler automatically collects Tariff % × Modified GTV in gold pieces as pure tax revenue into the kingdom's treasury.

3. Roll Available Cargo Lots: Roll 1d20 three times on the Exotic Import/Export table to see which specific bulk items are available for players or local merchant syndicates to purchase, speculate on, or ship to standard terrestrial markets downriver.

This d20 table is designed for Levels 4–6 of Skull Tower, targeting mid-level parties (Levels 4–7). In accordance with the ACKS II dungeon ecology framework, this table combines both concrete monster encounters (with quantities scaled to tactical threat parameters) and systemic environmental events that shift the dungeon's logistical state.

Skull Tower: Levels 4–6 Wandering Monster & Event Table

| d20 | Encounter / Event Type | Details & ACKS II Mechanical Scaling | | :---: | :| :| | 1 | Phraint Vanguard | 1d4 Phraints. AC 5, HD 3+3, Att 1 × weapon (greatsword or composite bow), Move 120ft, SV F4, ML +1, AL Neutral. Highly coordinated insectoid warriors. They leap up to 30ft into combat, gaining a +2 to hit on charge attacks. They are hostile only if the party interferes with their current hunting mission. | | 2 | Deodand Pack | 1d6 Deodands. AC 4, HD 4+2, Att 2 × claws (1d4), 1 × bite (1d6), Move 120ft, SV F4, ML +2, AL Chaos. Carnivorous, pitch-black humanoids that radiate unnatural malice. They surprise on a 1–4 on 1d6. If they hit with both claws, their bite attack deals double damage. | | 3 | Techno-Scavenger Squad | 1d4+1 Rival Human Technos (Level 3). AC 6 (Mesh Vest), HD 3, Att 1 × Laser Pistol (1d6+1) or vibro-blade (1d6), Move 120ft, SV T3, ML 0, AL Neutral. Armed with 1st-level Schematics. They are actively hunting for Technic Salvage and will try to extort, rob, or ambush the party if they think they have the upper hand. | | 4 | Thrak Marauders | 1d3 Thraks. AC 7 (Chitin), HD 6, Att 1 × massive pincer (2d6) or weapon, Move 90ft, SV F6, ML +1, AL Chaos. Brutal, reptilian-insectoid hybrids. They possess a high strength threshold; any target hit by a pincer must make a Save vs. Paralysis or be pinned (unable to move, taking automatic pincer damage each round until they break free). | | 5 | Dimensional Shambler | 1 Shambler. AC 5, HD 5, Att 2 × claws (1d8), Move 60ft, SV F5, ML +3, AL Chaos. A cosmic horror that steps through solid walls via phasing rifts. It is immune to non-magical or non-technic weapons. If it hits a target with both claws, it attempts to grapple and phase them into a hostile pocket dimension on the following round (Save vs. Spells to resist). | | 6 | Cybernetic Zombie Pack | 2d4 Cyber-Zombies. AC 3 (Steel Plating), HD 2, Att 1 × slam (1d6) or rusted bayonet (1d6), Move 60ft, SV F1, ML N/A (Fearless), AL Chaos. Reanimated corpses augmented with crude cybernetics. They do not check morale. They take half damage from piercing weapons but are highly vulnerable to electrical or EMP attacks, which instantly short-circuit them. | | 7 | Lathi Stalker | 1 Lathi. AC 6, HD 7, Att 2 × claws (1d6), 1 × energy lash (1d10), Move 150ft, SV F7, ML +2, AL Chaos. A shifting, predatory entity from the deep outer voids. It can turn completely invisible at will (Hide in Shadows 85%). Attacks out of invisibility grant it a +4 to hit. | | 8 | Kobbit Tunneling Party | 2d6 Kobbits. AC 2, HD 1-1, Att 1 × shortsword (1d6) or sling (1d4), Move 90ft, SV T1, ML -1, AL Neutral. Distant, hyper-cautious sub-terran relatives of halflings. They are mapping the level. They are entirely non-hostile unless cornered and will gladly trade accurate mapping data regarding nearby traps for standard rations or shiny junk. | | 9 | Malfunctioning Defense Drone | 1 Hover-Drone. AC 8 (Skittering Skiff), HD 4, Att 1 × Pulse Laser (1d8), Move 150ft (Fly), SV F4, ML N/A, AL Neutral. A floating security automated unit with a fried targeting matrix. It fires indiscriminately at any moving organic creature within 90ft. It can be looted for 1d3 intact Power Cells if disabled without being blown up. | | 10 | Star-Refugee Mercenaries | 1d3 Alien Humanoids. AC 4 (Deflector Fields), HD 5, Att 1 × Plasma Rifle (2d6), Move 120ft, SV F5, ML +1, AL Neutral. Out-of-work dimension travelers looking for a way home. They can be hired as elite retainers for the duration of the dungeon delve if the party pays them a premium upfront fee of 500gp per level in pure silver, gold, or functional tech components. | | 11 | Event: World Gate Backwash | The floor trembles as a distant nexus gate cycles open on an adjacent level. A wave of chronal distortion washes through the corridor. All active spell durations, light sources, and active Techno Schematics are instantly reduced by 1d4 turns as time briefly dilates. | | 12 | Event: Radiation Leak | The party steps into a zone contaminated by a ruptured power conduit from an ancient machine room. All characters must immediately make a Save vs. Poison/Radiation. Failure results in the immediate loss of 1d4 Constitution points due to cellular sickness (restorable only via high-level Cleanse magic or advanced medical stims). | | 13 | Event: Faction Skirmish | The party encounters a chaotic battlefield mid-corridor: 1d4+1 Phraints are actively locked in a lethal melee combat against 1d6 Deodands. The party can choose to intervene to gain favor with a faction, sneak past during the chaos, or ambush the survivors. | | 14 | Event: Gravity Inversion Zone | The artificial gravity grid in this 60-foot stretch of hallway fails completely. Gravity shifts upside down for 2d6 rounds. Anyone in the area takes 1d6 falling damage as they plummet to the ceiling. Movement is reduced to a crawl (one-fourth speed) unless characters have magnetic footwear or levitation. | | 15 | Event: Technic Scavenge Node | The party stumbles onto the structural wreckage of a destroyed extra-dimensional pod or machine interface. A Techno or character with Ancient Lore (Technology) can spend 1 turn to roll a scavenging check, yielding 2d6 × 100gp worth of Technic Salvage Value (SV). | | 16 | Event: Temporal Echo | The ghostly, translucent apparitions of a high-level adventuring party from 100 years in the future (or past) walk straight through the corridor, speaking in an unknown language. They ignore the PCs completely, but watching their path reveals the exact location of a hidden pit trap further down the hallway. | | 17 | Event: Power Grid Overload | Wall panels crackle with blue static electricity. All electronic gear, blasters, and active power suits spark violently. Every power cell currently carried by the party loses 1d3 active charges due to sudden magnetic drainage unless stored in lead-lined shielding bags. | | 18 | Event: Toxic Slime Inundation | A rusted overhead conduit bursts open, flooding the path ahead with a slow-moving wave of neon-green acidic slime. The corridor is impassable for the next 2d4 hours unless the party uses plasma torches or magical fire to scorch a path through the caustic sludge. | | 19 | Event: Market Scout Caravan | A strange merchant entourage from the Skull Tower Surface Citadel approaches. Led by a cloaked High-Elf trader and escorted by robotic guards, they are willing to buy dungeon treasures or sell basic adventuring gear and standard ammunition at a 50% markup. | | 20 | Event: Spatial Fold | The layout of the dungeon twists dynamically. The door or corridor the party just passed through now connects to a completely different room on the opposite side of the map level. Returning to safety requires navigating an entirely new path forward. |

Implementation Guidelines for the Judge

1. Encounter Frequency: Roll a d20 once every 2 turns (20 minutes) of exploration time while the party is navigating the mid-levels of the tower. An encounter or event occurs on a roll of 1–3.

2. Morale Modifications: Arduinian creatures are notoriously stubborn or unpredictable. If a monster roll indicates a Chaos alignment, they will rarely check morale until their group has been reduced to one-third of its original starting numbers.

3. Tracking Salvage Value: Any defeated mechanical entity (such as the Hover-Drone or Cyber-Zombies) can be harvested for raw parts using the ACKS II component rules, providing structural wealth to fuel a Techno's workshop fabrication projects.

OSR Commentary - Breakdown & Details of Using or Playing Stars Without Number With The Cepheus Engine Rpg

 Stars Without Number (SWN), designed by Kevin Crawford of Sine Nomine Publishing, is a sci-fi tabletop RPG built from the bones of old-school fantasy gaming (specifically classic B/X D&D) but adapted for sandbox space opera.

It is widely celebrated as one of the best toolkits for game masters running open-ended, emergent campaigns. Here is a detailed breakdown of how the system functions across its core components.

1. The Engine: Bimodal Resolution

SWN uses a distinct bimodal dice mechanic to differentiate the tension of life-or-death combat from the predictable competency of professional skills.

• Combat (d20): Attack rolls use a standard $1d20 + \text{Attribute Modifier} + \text{Attack Bonus}$. It targets the enemy's Armor Class (AC), where higher is better in the Revised Edition. Combat is lethal, fast, and swingy.

• Skill Checks (2d6): Out-of-combat tasks use $2d6 + \text{Attribute Modifier} + \text{Skill Level}$ against a target difficulty (Difficulty Class). The bell curve of 2d6 ensures that characters who are skilled pilots, hackers, or engineers perform reliably under pressure, reducing random failures for trained specialists.

• Saving Throws: Characters have three saving throws rolled on a d20: Physical, Evasion, and Mental. The target numbers scale down as characters level up, making them naturally more resilient.

2. Character Generation & Archetypes

Characters are highly customizable despite a streamlined class system. Attributes follow the traditional six stats (Strength, Dexterity, Constitution, Intelligence, Wisdom, Charisma), generated by rolling 3d6 in order, though players can raise one prime attribute to 14 to ensure viability.

There are four primary classes:

• The Expert: The master of non-combat utility. They gain extra skill points and possess a unique class ability to reroll one failed skill check per scene.

• The Warrior: The frontline combatant. They possess higher combat bonuses and a crucial class ability: once per scene, they can completely negate a successful hit against them or turn a missed attack of their own into a hit.

• The Psychic: The wielder of psionic disciplines (Biopsionics, Telekineses, Telepathy, Teleportation, Precognition, Metapsionics). They manage a pool of Psi Points and can choose to "torch"—risking permanent attribute damage to fuel powers when out of points.

• The Adventurer: A customizable hybrid class allowing players to multiclass (e.g., a Warrior/Psychic "Jedi" archetype or an Expert/Warrior mercenary).

Characters are further defined by a Background (which gives starting skills) and Foci (equivalent to feats or talents, providing specialized perks like sniper training, diplomatic grace, or starship piloting expertise).

3. Starship & Space Combat

Starship travel and combat are tightly structured to involve the whole crew rather than just the pilot.

• Spike Drives: Ships travel between systems using spike drives to cross the interstellar void, shifting into "metaspace." Navigation requires astrogation skill checks, and bad jumps can strand a crew in deep space.

• Command Point Economy: In space combat, the ship generates a pool of Command Points (CP) each round based on the captain's leadership and the ship's bridge performance. Every player occupies a station (Bridge, Gunnery, Engineering, Comm Station, Flight Deck) and spends CP to execute specific departments' actions—such as evasive maneuvers, firing lasers, or clearing electronic interference. This ensures no player sits idle during space encounters.

4. Sandbox Sector Design

For the GM, SWN provides a comprehensive engine for procedurally generating a sector of space. The system layout usually begins on a 5x6 or 8x10 hex grid.

Each planet generated receives two World Tags. These tags are thematic archetypes (e.g., Cybercommunist, Forbidden Tech, Unspotted Colony, Police State). The rulebook details every tag with pre-generated lists of:

• Friends and Enemies native to that setting.

• Places of interest.

• Complications that disrupt straightforward missions.

• Things or treasures unique to that ecosystem.

Combining two disparate tags (like Pretech Cultists + Ocean World) instantly generates a distinct, conflict-driven setting with minimal GM overhead.

5. The Interstellar Faction Turn

One of SWN's most acclaimed innovations is the Faction Turn, a minigame played by the GM between game sessions.

The GM creates the major power players of the sector—megacorporations, planetary governments, mercenary bands, or alien empires—and assigns them attributes (Force, Cunning, Wealth) and a Goal.

[Faction Setup] ──> [Income Phase] ──> [Asset Purchase] ──> [Action Resolve]
      │                                                              │
      └─────────────────── Players Intercept Actions ────────────────┘

Factions use their stats to buy Assets (such as Black Ops Teams, Blockade Fleets, Smuggler Networks, or Local Media Control) and move them around the sector map to attack, defend, or exploit resources.

Because this happens systematically behind the scenes, the universe responds dynamically to the passage of time. If the players ignore a rising military cult on a distant moon, the Faction Turn resolves what happens next naturally, shifting the political landscape and generating organic news reports and adventure hooks for the next session.

6. System Modularity & Compatibility

Because the underlying skeleton relies on classic D&D mechanics, SWN is incredibly easy to hack. You can import modules, monsters, dungeon-stocking procedures, and encounter tables from classic fantasy OSR systems or older editions of D&D with negligible translation. The game scales seamlessly from gritty, low-tech survival on isolated worlds (Tech Level 0–2) to high-tech space operas involving artificial intelligences, starship fleets, and ancient pre-apocalypse relics (Tech Level 4–5).

Combining Stars Without Number (SWN) with the Cepheus Engine (an open-source system based on classic 2D6 sci-fi gaming like Traveller) creates an exceptionally robust sandbox. SWN provides the gold standard for faction turn mechanics and sector generation, while Cepheus Engine brings gritty, simulationist career backgrounds and granular, hard-sci-fi rules for gear, economics, and trade.

Because both systems trace their roots back to the late 1970s and early 1980s, they share structural similarities that make them surprisingly compatible. Here is how to blend them into a unified campaign framework.

1. Unified Resolution: The 2D6 Bridge

The easiest way to combine the two games is to use the Cepheus Engine / 2D6 system as the primary engine for characters and tasks, while reserving SWN's d20 mechanics purely for specific baseline structures if needed.

Conveniently, SWN already uses a 2D6 system for its non-combat skill checks.

• Skill Checks: Both games naturally align here. A standard check becomes:

  $$2d6 + \text{Cepheus Skill Level} + \text{Attribute Modifier} \ge \text{Target Difficulty}$$

  A typical target difficulty in Cepheus is 8+.

• Attributes: Cepheus Engine uses the traditional Universal Character Profile (UCP) stats: Strength, Dexterity, Endurance, Intelligence, Education, and Social Standing. You can map SWN's attributes directly to these, swapping Wisdom for Education and Charisma for Social Standing.

2. Character Generation: Lifepaths vs. Foci

Cepheus Engine features a famous, semi-random lifepath system where characters roll for terms of service in careers (e.g., Scout, Navy, Merchant, Rogue) to acquire skills, rank, and benefits.

To bring SWN's flavor into this framework:

• Backgrounds & Careers: Use the Cepheus Engine lifepath to generate a character’s career history and core skills.

• Injecting SWN Foci: To give characters the specialized, heroic flavor of SWN, grant every character one Free Focus at character creation, and another if they choose a specific feat-like benefit during their career muster-out phase. Foci like Die Hard, Specialist, or Starfarer port cleanly into Cepheus—simply translate any SWN "Skill Bonus" into a +1 to the equivalent Cepheus skill.

[Cepheus Lifepath Generation] ──> [Acquire Career Skills] ──> [Select 1-2 SWN Foci] ──> [Final Character]

3. Integrating Psionics

Psionics are handled quite differently in both systems. Cepheus treats psionics as rare, dangerous, and mechanically rigid, requiring a distinct "Psi" attribute. SWN treats psychics as a core character class with highly structured, leveling disciplines.

• The Hybrid Solution: If a player wants an SWN-style psychic in a Cepheus game, use the Cepheus lifepath but replace their career training with SWN Psionic Disciplines.

• The Resource Pool: Use the character's Cepheus Psi or Intelligence characteristic to establish their maximum Psi Point pool. They can use SWN techniques (like Biopsionics or Telekinesis) by spending points from this pool, using a Cepheus 2D6 check + Psionic skill to activate more difficult powers under stress.

4. Starship Scale and Space Combat

Cepheus Engine has hyper-detailed ship component rules, vector-based movement options, and distinct trade tables. SWN features a highly streamlined starship combat engine built around crew actions.

System Element	Recommended Source	Why It Works
Ship Design & Specs	Cepheus Engine	Provides highly granular displacement tonnage, component modularity, and realistic hard-sci-fi hardpoints.
Space Combat Flow	Stars Without Number	The SWN Command Point (CP) economy is vastly superior for keeping every player active at their bridge station (Pilot, Gunner, Engineer) rather than just the pilot and gunner.
Interstellar Travel	SWN (Spike Drives)	SWN's "Metaspace" routing fits perfectly into a hex-grid sandbox map, requiring skill checks that match the Cepheus 2D6 curve.

To use SWN space combat in Cepheus, simply use the ship's Cepheus hull points and weapon damage dice, but use the SWN department actions to structure the rounds.

5. Economy, Trade, and Factions (The Perfect Marriage)

This is where the combination shines brightest. Cepheus Engine provides a robust Speculative Trade system (buying low on agricultural worlds, selling high on industrial worlds). SWN provides the living universe to react to that trade.

• World Building: Use SWN's World Tags to define the narrative hooks and immediate local conflicts of a planet. Then, use Cepheus Engine's Universal World Profile (UWP) codes to determine the strict planetary statistics: population sizes, tech levels, government types, and starport classes.

• The Interstellar Economy: Let players use Cepheus trade tables to run cargo freighters across the sector.

• The Living Sandbox: Run the SWN Faction Turn in the background between sessions. If the Faction Turn dictates that a Megacorporation launches a "Blockade Asset" against a rival world, the Cepheus starport class drops, prices spike for incoming goods, and the players' trade routes instantly face physical danger.

By running these systems together, the players' mechanical actions (like smuggling cargo or hiring mercenaries using Cepheus rules) can directly damage or aid the Factions operating under SWN rules.

Blending the starship travel mechanics of Stars Without Number (SWN) and the Cepheus Engine allows you to combine the gritty navigation, fuel management, and structural risks of classic 2D6 sci-fi with the dynamic, hex-mapping exploration of SWN's "Metaspace."

Here is how to blend the two systems into a unified interstellar travel framework.

1. The Core Concept: Spike Drives vs. Jump Drives

In Cepheus, ships use a Jump Drive fueled by liquid hydrogen to instantly cross a set number of parsecs (hexes) over exactly one week. In SWN, ships use a Spike Drive to drill into a hyperspace dimension called Metaspace, taking days or weeks to navigate hazardous currents.

To blend them, adopt SWN's Spike Drives and Metaspace routing, but use Cepheus Engine's 2D6 skill curves, fuel requirements, and maintenance costs.

• Spike Drive Ratings: The Drive rating (Spike-1 to Spike-6) dictates the maximum distance a ship can cross in a single uninterrupted drill (e.g., a Spike-2 drive can cross up to 2 hexes).

• Travel Time: Instead of Cepheus’s rigid "always one week," use SWN's variable travel times based on the drive rating and distance, which adds tension when beating a faction's timeline matters.

2. The Travel Sequence (Step-by-Step)

1.Plot the Course (Astrogation):2D6 Check.

The navigator plots a course through metaspace. Roll 2D6 + Education Modifier + Astrogation Skill.

• Known Route: Difficulty 6+

• Uncharted Space: Difficulty 9+

• Failure: The ship still enters metaspace but encounters a complication (increased travel time, minor system damage, or an immediate hazard encounter).

2.Burn the Fuel (Cepheus Logistics):Fuel Allocation.

Instead of SWN's abstract fuel cells, apply Cepheus's logistical weight. A spike drill requires refined or unrefined hydrogen fuel. The drive consumes 10% of the ship's total hull tonnage per hex traveled, or a flat rate based on your chosen Cepheus ship design framework.

3.The Drill (Metaspace Transit):Days in Transit.

The ship enters metaspace. Calculate the transit time using the drive rating. During this time, the crew is cut off from the real universe.

4.The Emergence (System Ingress):Realspace Arrival.

The ship exits metaspace at the destination system's rim (the gravity well limit). The pilot must then spend $1d4 \times 6$ hours traveling sub-light to reach the inner planets.

3. Integrated Travel Complications

Use a 2D6 curve to determine what happens if a navigator fails their Astrogation check or drops out of metaspace into an uncharted hex.

2D6 Roll	Metaspace Event / Complication	Mechanical Effect (Blended)
2	Drive Failure / Misjump	The drive suffers a critical hit (Cepheus damage tables). The ship drops out in interstellar space; a repair is required before drilling again.
3-5	Metaspace Turbulence	The journey takes $1d6$ extra days. The drive strains, consuming 20% more fuel.
6-8	Standard Transit	Arrive on schedule with no unexpected stress on the ship's systems.
9-11	Smooth Wake	Exceptional navigation cuts travel time by 25%. Save 10% on fuel consumption.
12	Metaspace Current	The ship catches a rift current. Arrive in half the time, and the navigator gains a +1 forward on their next Astrogation check along this route.

4. Interstellar Travel Times

To keep the scale feeling vast, use this blended matrix for travel times based on distance and Spike Drive efficiency:

• Distance: 1 Hex = 1 Parsec.

• Formula: $\text{Base Time} = \frac{\text{Distance in Hexes}}{\text{Spike Drive Rating}} \times 3 \text{ Days}$

Example: A ship with a Spike-2 Drive attempting a 3-Hex jump through a charted route will consume fuel for 3 hexes and spend 4.5 days in metaspace transit, provided the navigator passes their 2D6 Astrogation check.

5. Tying Travel to the Faction Turn

This blended approach directly impacts the sandbox map. When a player uses Cepheus Engine's trade rules to jump from system to system, their travel times dictate exactly how many SWN Faction Turns occur in the background. If a trade run takes two weeks of round-trip travel, the GM runs a Faction Turn, meaning the market prices, local blockades, or political stability of the destination world may shift by the time the players drop out of metaspace.